Mission San Juan, San Antonio Missions National Historical Park, Texas.

MISSION SAN JUAN at San Antonio Missions National Historical Park, Texas, is situated approximately one-third mile from the end of the Stinson Municipal Airport runway. The noise from aircraft passing overhead shortly after takeoff is a concern to park managers seeking to preserve the contemplative atmosphere in which visitors can enjoy the mission and its grounds. In 2007, the airport applied to the Texas Department of Transportation to lengthen the runway to 5,000 feet and update the terminal to accommodate greater general aviation use. The airport provides relief to the commercial airport in San Antonio and is economically important for the city. The National Park Service opposed the proposed expansion, noting that it would constitute a "constructive use" of the park by increasing noise encroachment, vibration, and the risk of aircraft accidents. The Texas Department of Transportation approved the request, and expansion of the runway and airport are now under way. In May 2008, Natural Sounds Program staff sampled the sound environment at the mission, establishing a baseline for comparison of changes in noise after the runway becomes operational in 2010.